“Prison,” Nadezhda Tolokonnikova said in her interview with GQ, “is like a monastery—it’s a place for ascetic practices.” Member of the celebrated but incarcerated band Pussy Riot, Tolokonnikova gave voice to the belief that prison can be a soul-changing institution: an idea that inspired the American penal system.

The same year that America declared its independence from Great Britain, Philadelphia’s Walnut Street Jail opened. Its first major addition came in 1790 at the instigation of Quaker reformers who proposed “a penitentiary house” of sixteen individual cells for solitary confinement.

The penitentiary, unlike jails or prisons, set itself to the task of rehabilitating prisoners. Religious penance became the paradigm for criminal punishment; the monastic chamber served as the model for the prison cell. Walnut Street exemplified the philosophy of what became known as the Pennsylvania System, which separated prisoners from one another while enforcing silence and manual labor as mechanisms for transformation.